U.S. Pat. No. 5,003,288 to Wilhelm concerns a detection and warning system for use in a motor vehicle. This patent describes a system where ambient light levels are monitored and in the event the monitored light levels fall below a threshold level, a warning indicator is activated. Preferably a warning lamp is activated to apprise the motorist that the headlamps have not been turned on and that the ambient light conditions indicate that the lamps should be turned on. The disclosure of the '288 Wilhelm patent is incorporated herein by reference.
The '288 patent discloses circuitry for responding to an input signal from a light sensor and activating a visual indicator such as a light bulb. The light bulb is caused to flash to bring to the attention of the motorist the fact that ambient light conditions are insufficient for safe driving. A preferred mechanism for causing the light bulb to flash includes a timer circuit that responds to the receipt of a control input by flashing a light bulb at a controlled rate based upon external components coupled to the timer circuit.